Weldable Low-Alloy Mn-Mo-Nb Steels with a High Elastic Limit.

A newly developed high-strength, weldable, low-carbon (0. 06% C) Mn-Mo-Nb structural steel is discussed. The effect of the rolling conditions during the thermomechanical treatment of this steel on its structure and mechanical properties is illustrated. A further development of this steel for applications such as pipeline construction with minimum tensile yield strength of 500 N/sq mm is described. In addition, the stress-strain behavior and the effect of some cold deformations on the toughness properties is discussed, and welding test results with cellulose-coated electrodes at welding temperatures as low as minus 30 degree C are presented.